On trial

Adolescent minds, social influence and the new puberty blockers trial

A thought experiment: if you were a policy maker charged with working out whether to offer powerful drugs that block puberty to gender-questioning adolescents, would you (a) dole them out anyway, without looking too closely at evidence, (b) gather and assess carefully the bountiful, yet imperfect, evidence that already exists about benefits and harms, or (c) subject a new cohort of teenagers and almost-teenagers to the drugs to test what happens to them, replicating almost exactly research that’s already been done?

You’ll have spotted from the framing of my question that I have an answer in mind. It’s my Substack; I get to ask leading questions occasionally.

A controversial NHS trial of puberty blockers for adolescents with ‘gender incongruence’ was paused in February after the medical regulator warned of the ‘unquantified risk of long-term biological harms’. The trial, known as PATHWAYS, has now been unpaused, with recruitment due to start in August. But the biological risk is present, whether quantified or not.

Briefly, as this piece is mainly about the ill-considered psychosocial risks of the trial and its blocking of puberty, the physical risks of puberty blockers and cross-sex hormones are well known. A whistle-stop tour: puberty blockers affect bone health and limit growth. They can cause hot flushes, high blood pressure, fatigue, mood swings, memory loss and weight gain. They may well negatively affect brain development. When combined with later cross-sex hormone treatment, long-term consequences include impaired sexual function, infertility and worse cardiovascular health.

Wouldn’t you need pretty strong evidence of positive psychosocial outcomes to warrant converting these known risks into reality through a new trial? We’ll come back to the answer to this question.

There’s much that could be said against the prescription of these drugs, but I want to focus on some of the potential effects of the ban as they relate to adolescent minds and social influence. Here are a few concerns:

1. The trial will irreversibly reshape adolescents’ bodies to match a mental state that might otherwise have passed. Without social and medical intervention, older cases of gender distress tended to resolve themselves with age. Identity shape-shifts across the teenage years and into adulthood, and yet almost all adolescents who take puberty blockers go on to take cross-sex hormones and to experience their irreversible effects. A transient state is made permanent.

Iatrogenesis means harm caused by treatment. It has been argued in peer-reviewed research that social and medical transition causes iatrogenic gender dysphoria, exacerbated by the physical harms of treatment. Referral rates to gender identity services have shot up across multiple countries since 2010, suggesting a strong role for social, and potentially medical, influence: advertising the supply of treatment may be increasing the demand for it.

Detransitioners – people who went through medical treatment for gender-related issues but later accepted their sex – appear to be growing in number. Long-term symptoms experienced by detransitioners as a result of treatment include vaginal atrophy and clitoral pain in women, urinary dysfunction and breast enlargement in men, and infertility in both sexes. Detransitioners’ healthcare needs are complex, and they lack specialist support.

‘[A] study that included 952 transgender adolescents and adults in the US military healthcare system found 29% discontinued hormonal therapies within four years… Regret can take up to 10 years to materialize (Dhejne et al., 2014; Wipes et al., 2018), so these numbers likely underestimate the full scope of regret and detransition.’ – Jorgensen (2023)

2. The trial will, in some cases, amplify distress. If you think back in time to the mists of your own puberty, you might recall some generalised distress about newly emerging or rapidly changing body parts. Would someone drawing attention to these have made you more or less distressed? One batch of questions that will be asked of PATHWAYS participants focuses on 33 body parts, asking respondents to rate their feelings towards each part (including breasts, vagina, scrotum and penis) and whether they would want to change them using medicines or surgery if it were possible for them to do so. Trial questions may also exacerbate detachment from reality – asking, for example, if they are ‘mainly a boy’ or ‘neither a boy or girl’.

Gender-related distress is more likely to affect vulnerable adolescents – including those with autism and other psychological difficulties, those who’ve grown up in care and those who have been abused. These data imply a need for psychological care and support, not medication. If puberty blockers and later cross-sex hormones replace tailored, targeted support that takes into account individuals’ particular developmental histories and needs, they will be left without proper help for underlying issues. I’ve linked to an extensive evidence base in this paragraph, but sometimes an individual quote can explain a situation in a different way. According to a detransitioner interviewed for research published in the International Journal of Transgender Health:

‘I do truly wish that someone… had said, “We just gave you a prescription for Wellbutrin for depression that isn’t related to your gender identity. This may not be the best time to explore something with permanent ramifications. Do you think that this… dysphoria is part of a greater situation for you?” I think that would have been immensely helpful instead of just… affirming me.’

3. The trial will also amplify placebo effects and create other nocebo effects. The psychosocial effect of adolescent gender medicine is no greater (and possibly lower) than the placebo effect in comparable adolescents, according to analysis I conducted in 2022 for Sex Matters. Clinician researchers, including the Australian psychiatrist Alison Clayton, have suggested that the placebo effect underlies some of the tiny, inconsistent benefits seen in research on adolescent gender medicine. According to an article published in the Journal of Sex and Marital Therapy last year:

‘While the benefits and certainty of [gender affirmative treatment] are exaggerated, its risks are insufficiently presented, and alternative treatment options are disparaged… While there is a more realistic narrative in peer-reviewed journals and the research community that highlights uncertainty and a lack of evidence, public communications offer an unrealistic narrative. This narrative exaggerates the certainty of benefits and the strength of evidence, thus amplifying the placebo effect.’

There’s a lot of noise already suggesting that puberty blockers are necessary, even to the point of being able to live. Good Law Project director Jolyon Maugham, for example, said that the proposed ban would ‘kill trans children’, a claim that has been comprehensively discredited by an independent review.

A thoughtful harm-benefit analysis of puberty blockers, using the substantial evidence that we already have, would likely conclude that there are insufficient evidenced benefits to counter-balance the known harms, a determination that would support gender-distressed adolescents and their families to benefit from alternative treatment options.

Going ahead with the trial, on the other hand, will potentially cause temporary placebo effects in trial participants. Nocebo effects (the placebo effect’s dark underbelly: expecting harm causes it) may well arise in the trial’s comparison group, members of which have to wait a year before beginning treatment, and in those who don’t qualify for the trial. Placebo effects tend to be shorter-lived than nocebo effects – expectation-induced harms may outlast expectation-induced benefits.

4. The trial lends weight to unevidenced belief systems. In other areas of medicine, drugs tend to be prescribed on the basis of evidence, not belief. The only basis for the prescription of puberty blockers and cross-sex hormones is a child’s belief that his or her ‘gender’ (a concept for which there is no objective measure and that others might define as ‘personality’) is different from his or her sex.

Sex is observable and measurable; gender identity is not. Young minds tend to follow the signals that adults provide for them. If clinicians are basing healthcare decisions on activist narratives, not evidence, belief in the ideology becomes reinforced among their patients.

5. The trial entrenches stereotypes and creates a paper conversion of its patient cohort from gay to straight. When children present on the basis of gender non-conformity, which is more likely in those who grow up to be same-sex attracted, the trial will medicalise their lack of adherence to restrictive stereotypes. Same-sex attracted teenagers make up the majority of gender-service referrals. The puberty blocker trial would lead to these teenagers being given drugs that help them to present as ‘straight’. This is regressive homophobia in a progressive cloak.

The remainder – the minority who are attracted to the opposite sex – are socialised into perceiving themselves as future lesbians, if they are natal boys; or gay men, if they are natal girls. But plenty of people, including many of these teenagers’ hoped-for future partners, would say that males cannot become lesbians or straight women; and that females cannot become gay or straight men.

Romantic and sexual disappointment gets future-proofed. It adds a further preventable and devastating layer to the inability to orgasm to which puberty blockers and cross-sex hormones can lead.

* * *

Supporters of the trial say we need more data. There’s one data source that hasn’t yet been properly mined: information about the long-term outcomes of the children, now adults, who were previously treated with puberty blockers and cross-sex hormones. What happened to these individuals? How is their mental and physical health? How else did this treatment affect them? How many have subsequently detransitioned? A ‘data linkage’ study could be performed using existing datasets, but it’s been blocked by adult NHS gender services. The Government changed the law in March to encourage their compliance, but we’re still a long way from knowing where these children ended up in adulthood.

Many have argued that researchers should be seeking to understand long-term outcomes of these existing cohorts rather than subject a new generation to an experimental treatment with known harms. There’s also rich and apparently unreported data available from the GIDS programme itself.

In 2015, for example, Rosalia Costa and colleagues at GIDS published a study using a similar design to the proposed trial. It too had a comparison group, the difference being that it wasn’t randomised; and it lasted for 18 months rather than two years. Perhaps the Costa findings have been ditched because of irredeemable methodological flaws. While there was a small difference in psychosocial functioning between the two groups, they weren’t comparable in the first place: the comparison group had ‘possible comorbid psychiatric problems and/or psychological difficulties’, so their difficulties may well have been more entrenched.

Most participants dropped out of the Costa study, but researchers used their scores anyway. 201 adolescents were involved at the start of the research; 71 were still there at the end. You can’t fairly compare before-and-after scores if you include the 130 drop-outs in the baseline data. They might have dropped out because their psychosocial functioning got worse, or because they suffered from adverse events, or because they changed their minds about treatment. The only way you can really compare data is within the same group of individuals – the 71 who made it to the end of the research.

Strangely, these data were not reported. Presumably they are out there, along with other previously unpublished data held by the former GIDS (authors of the University of York systematic review on puberty blockers, commissioned as part of the review into gender identity services by Hilary Cass, do not appear to have had access to this data: of the Costa study, they point out that it comprised a ‘small sample, limited analyses, and little detail’). Why are the PATHWAYS commissioners not seeking out this information alongside the data linkage study?

I’ll return now to my placeholder suggestion that we’d need strong evidence of positive psychosocial outcomes to warrant converting known risks into reality via a new trial. We do not have this. Evidence of positive outcomes is patchy and small; some studies (such as this one) even show a headline fall in psychosocial health after taking puberty blockers. Evidence of benefit is entirely absent over the long term, as data have not been collected. According to the York systematic review:

‘There is insufficient and/or inconsistent evidence about the effects of puberty suppression on… mental and psychosocial health.’

Supporters of the trial might argue that it will help to fill this gap. It cannot: its design means that it’s likely to replicate the tiny positive or negative movements in psychosocial outcomes that have been seen in previous studies. And it tells us nothing meaningful in terms of what puberty suppression does to young bodies and minds over the medium or long term. That is the consequential piece, and it’s what the data linkage study can help to answer.

If the puberty blockers trial can tell us nothing meaningful, its commissioning seems like a political decision – a seemingly neutral avoidance tactic to delay the inevitable conclusion that the benefits of adolescent gender medicine do not and cannot outweigh its considerable harms. We know this already.

The precious political benefits come at a heavy price, to be paid not by politicians, researchers or clinicians, but by a new cohort of distressed adolescents.

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Evidence-Based Parenting is available here and Teenagers: The Evidence Base can be found here.

Information about my next book will be available on this Substack later in 2026.